Preparation of monochloromethyl ketones

Abstract

A process for the production of a monochloromethyl ketone of the formula ##STR1## in which R 1 , R 2 and R 3 each independently is a hydrogen atom or an optionally substituted alkyl, alkenyl, alkinyl or aryl radical, or R 1 and R 2 together with the carbon atom to which they are attached form an optionally substituted carbocyclic ring, comprising reacting a 1,1-dichloroalkene of the formula ##STR2## with a phenolate of the formula ##STR3## in which R 4 each independently is a halogen atom, a nitro group, or an optionally substituted alkyl, alkoxy or aryl radical, n is 0, 1, 2 or 3, and M is one equivalent of an alkali metal ion or alkaline earth metal ion, thereby to obtain a phenyl ether intermediate, and then subjecting the phenyl ether intermediate to an acid hydrolysis. The products are useful as intermediates in the synthesis of fungicides.

We claim: 
     
       1. A process for the production of monochloromethyl ketone of the formula ##STR44## in which R 1 , R 2  and R 3  each independently is a hydrogen atom or an (optionally substituted) alkyl, alkenyl or alkinyl radical with up to 4 carbon atoms or an aryl radical, any of the foregoing being optionally substituted by halogen, phenyl, alkoxy with up to 3 carbon atoms or phenoxy, or R 1  and R 2  together with the carbon atom to which they are attached form a carbocyclic ring optionally substituted by methyl groups and/or alkoxycarbonyl groups with 1 to 3 carbon atoms, comprising reacting a 1,1-dichloroalkene of the formula ##STR45## with a phenolate of the formula ##STR46## in which R 4  each independently is a halogen atom, a nitro group, or an alkyl or alkoxy radical with 1 to 3 carbon atoms, or a phenyl radical,     n is 0, 1, 2, or 3, and   M is one equivalent of an alkali metal ion or alkaline earth metal ion, at from about 50° to 250° C. thereby to obtain a phenyl ether intermediate, and then subjecting the phenyl ether intermediate to an acid hydrolysis.     
     
     
       2. A process according to claim 1, wherein the reaction is carried out at a temperature between about 100° and 200° C. 
     
     
       3. A process according to claim 1, wherein the phenyl ether is of the formula ##STR47## is isolated and is purified before being subjected to the acid hydrolysis. 
     
     
       4. A process according to claim 1, in which: R 1  and R 2  each independently is an alkyl, alkenyl or alkinyl radical with up to 4 carbon atoms, or a phenyl radical, the radicals optionally being substituted by halogen, phenyl, alkoxy with up to 3 carbon atoms, or phenoxy, or   R 1  and R 2  together can form an alkylene chain with 2 to 7 carbon atoms optionally substituted by methyl groups and/or alkoxycarbonyl groups with 1 to 3 carbon atoms, and   R 3  is a hydrogen atom, or an alkyl radical with up to 10 carbon atoms or an aryl radical with 6 to 10 carbon atoms, either optionally substituted by halogen, nitro, alkoxy, alkyl, phenyl or cyano.   
     
     
       5. A process according to claim 1, in which: R 4  is a chlorine or fluorine atom, an alkyl or alkoxy radical with 1 to 3 carbon atoms, or a phenyl radical, the radical R 4  being located in the 2-position, 3-position and/or 4-position,   n is 0, 1 or 2, and   M is a sodium or potassium ion.   
     
     
       6. A process according to claim 4, in which: R 4  is a halogen atom, a nitro group, or an optionally substituted alkyl, alkoxy or aryl radical,   n is 0, 1, 2 or 3, and   M is one equivalent of an alkali metal ion or alkaline earth metal ion, the reaction is carried out at a temperature between about 100° and 200° C., and the phenyl ether intermediate is isolated and purified before being subjected to the acid hydrolysis.     
     
     
       7. A process according to claim 6, wherein R 1  and R 3  are methyl and R 2  is vinyl.